Management of a C-Shaped LR7 with a Large Buccal Deep Carious Defect

C-shaped canal systems represent one of the most challenging anatomical configurations encountered in endodontics, with a particularly high prevalence in mandibular second molars. The C-shaped morphology — characterised by a fin, web, or ribbon-like connection between canals — demands meticulous three-dimensional cleaning and shaping strategies. When combined with a large, deep buccal carious lesion that compromises structural integrity and complicates isolation, case complexity is significantly elevated. This case documents the full management of a lower right second molar (LR7) presenting with precisely this combination of challenges. Case Presentation A patient presented reporting spontaneous, lingering pain in the lower right posterior quadrant, exacerbated by thermal stimuli and biting pressure. Medical history was non-contributory. Intraoral examination revealed the LR7 with a large…